Anticancer actions of carnosine in cellular models of prostate cancer.

Treatments for organ-confined prostate cancer include external beam radiation therapy, radical prostatectomy, radiotherapy/brachytherapy, cryoablation and high-intensity focused ultrasound. None of these are cancer-specific and are commonly accompanied by side effects, including urinary incontinence and erectile dysfunction. Moreover, subsequent surgical treatments following biochemical recurrence after these interventions are either limited or affected by the scarring present in the surrounding tissue. Carnosine (ß-alanyl-L-histidine) is a histidine-containing naturally occurring dipeptide which has been shown to have an anti-tumorigenic role without any detrimental effect on healthy cells; however, its effect on prostate cancer cells has never been investigated. In this study, we investigated the effect of carnosine on cell proliferation and metabolism in both a primary cultured androgen-resistant human prostate cancer cell line, PC346Flu1 and murine TRAMP-C1 cells. Our results show that carnosine has a significant dose-dependent inhibitory effect in vitro on the proliferation of both human (PC346Flu1) and murine (TRAMP-C1) prostate cancer cells, which was confirmed in 3D-models of the same cells. Carnosine was also shown to decrease adenosine triphosphate content and reactive species which might have been caused in part by the increase in SIRT3 also shown after carnosine treatment. These encouraging results support the need for further human in vivo work to determine the potential use of carnosine, either alone or, most likely, as an adjunct therapy to surgical or other conventional treatments.

Incidencia de cáncer en pacientes ambulatorios con enfermedad pulmonar obstructiva crónica / Incidence of cancer in outpatients with chronic obstructive pulmonary disease

Introducción. La relación entre la enfermedad pulmonar obstructiva crónica (EPOC) y la incidencia global de cáncer es poco conocida. El objetivo del estudio fue analizar la incidencia de cáncer (tanto de localización pulmonar como extrapulmonar) en pacientes con EPOC en seguimiento en una consulta ambulatoria especializada, así como valorar su relación con el grado de obstrucción al flujo aéreo. Metodología. Estudio observacional prospectivo de una cohorte de 308 pacientes con EPOC en seguimiento en consultas ambulatorias de neumología durante el periodo comprendido entre enero de 2012 y diciembre de 2015. Las neoplasias diagnosticadas en este periodo se dividieron en pulmonares y extrapulmonares. Resultados. Las tasas de incidencia global de cáncer, de cáncer de pulmón (CP) y de cáncer extrapulmonar fueron de 10,3, 3,4 y 7,3 casos por 1.000 pacientes EPOC-año, respectivamente. Los tumores más frecuentes fueron el CP (31%), los del tracto genitourinario (29%) y digestivo (21%). Los estadios leve-moderado (gradosI-II de la GOLD 2009) y el incremento del índice paquetes-año (IPA) se relacionaron con un aumento en la aparición de neoplasias con un odds ratio (OR) de 2,16 (intervalo de confianza al 95% [IC95%]: 1,087-4,309; p=0,026) y 1,01 (IC95%:1,002-1,031; p=0,023), respectivamente. Conclusión. La incidencia de cáncer de localización extrapulmonar en pacientes con EPOC duplica a la de CP. Los estadiosI-II de la GOLD 2009 y el IPA se relacionan de forma significativa con la aparición de neoplasias (AU)

Introduction. The relationship between chronic obstructive pulmonary disease (COPD) and the overall incidence of cancer is poorly understood. The aim of this study was to analyse the incidence of cancer (pulmonary or extrapulmonary) in patients with COPD during follow-up in a specialised outpatient unit, as well as to assess its relationship with the degree of airflow obstruction. Methodology. A prospective observational study was conducted with a cohort of 308 patients with COPD in pulmonology outpatient follow-up consultations from January 2012 to December 2015. The diagnosed malignancies during this period were divided into pulmonary and extrapulmonary. Results. The overall incidence rate of cancer, lung cancer and extrapulmonary cancer were 10.3, 3.4 and 7.3 cases per 1,000 patients with COPD per year, respectively. The most common cancers were lung cancer (31%), genitourinary tract cancer (29%) and gastrointestinal cancer (21%). Mild-moderate stages (gradeI-II of the 2009 GOLD classification) and the increase in the pack-year index (PYI) were related to an increase in the onset of malignancies, with an odds ratio (OR) of 2.16 (95% confidence interval [95% CI]: 1.087-4.309; P=.026) and 1.01 (95% CI: 1.002-1.031; P=.023), respectively. Conclusion. The incidence of extrapulmonary cancer in patients with COPD was twice that of lung cancer; stagesI-II of the 2009 GOLD classification and the PYI were significantly related to the onset of malignancies (AU)

Incidence of cancer in outpatients with chronic obstructive pulmonary disease. / Incidencia de cáncer en pacientes ambulatorios con enfermedad pulmonar obstructiva crónica.

INTRODUCTION: The relationship between chronic obstructive pulmonary disease (COPD) and the overall incidence of cancer is poorly understood. The aim of this study was to analyse the incidence of cancer (pulmonary or extrapulmonary) in patients with COPD during follow-up in a specialised outpatient unit, as well as to assess its relationship with the degree of airflow obstruction. METHODOLOGY: A prospective observational study was conducted with a cohort of 308 patients with COPD in pulmonology outpatient follow-up consultations from January 2012 to December 2015. The diagnosed malignancies during this period were divided into pulmonary and extrapulmonary. RESULTS: The overall incidence rate of cancer, lung cancer and extrapulmonary cancer were 10.3, 3.4 and 7.3 cases per 1,000 patients with COPD per year, respectively. The most common cancers were lung cancer (31%), genitourinary tract cancer (29%) and gastrointestinal cancer (21%). Mild-moderate stages (gradeI-II of the 2009 GOLD classification) and the increase in the pack-year index (PYI) were related to an increase in the onset of malignancies, with an odds ratio (OR) of 2.16 (95% confidence interval [95% CI]: 1.087-4.309; P=.026) and 1.01 (95% CI: 1.002-1.031; P=.023), respectively. CONCLUSION: The incidence of extrapulmonary cancer in patients with COPD was twice that of lung cancer; stagesI-II of the 2009 GOLD classification and the PYI were significantly related to the onset of malignancies.

Impact of 13-valent pneumococal conjugate polysaccharide vaccination in exacerbations rate of COPD patients with moderate to severe obstruction. / Impacto de la vacunación neumocócica de polisacáridos conjugados 13-valente en las exacerbaciones de pacientes con enfermedad pulmonar obstructiva crónica con obstrucción al flujo aéreo moderada-muy grave.

OBJECTIVE: One of the major microorganisms described as the cause of exacerbations of chronic obstructive pulmonary disease (COPD) is Streptococcus pneumoniae. The aim of this study is to evaluate the impact of 13-valent pneumococcal conjugate polysaccharide vaccine (PCV13) on COPD patients with regard to the development of exacerbations and the possible differential effect according to the patient's phenotype. METHODS: Prospective observational study of patients with COPD and FEV1 ≤ 65% and 18-month follow-up. Main variables: vaccination status with PCV13, phenotype "exacerbator" or "non-exacerbator", number of exacerbations, hospitalization and deaths. A descriptive statistical analysis was performed according to the nature of the variable and an inferential analysis with CI95%, bivariate contrasts, and multivariate analysis. Significance level 5%. The statistical packages EPIDAT 3.0 and SPSS version 21.0 were used. RESULTS: 121 patients were included. Twenty-four percent were labeled as phenotype exacerbator. 36% were vaccinated with PCV13. During follow-up, 68% of patients had at least one exacerbation and 27% required hospitalization. We observed similarity (p> 0.05) in the number of exacerbations and deaths; however, the percentage of hospitalization in the vaccinated was 18%, compared to 32% in the non-vaccinated group. In the multivariate adjustment (controlling for the phenotype), an adjusted OR of 2.77 risk of hospitalization was observed in the non-vaccinated group (p = 0.044). CONCLUSIONS: Non-vaccination with PCV13 almost triples the risk of hospitalization in patients with COPD.

CIELAB color coordinates versus relative proportions of myoglobin redox forms in the description of fresh meat appearance.

This work examined changes in color that can be explained solely on the basis of the total myoglobin content and the relative proportions of deoxymyoglobin, oxymyoglobin (OMb) and metmyoglobin (MMb) during storage of meat. Meat color was evaluated for L*, a*, b*, C* and hab. Total pigment content was measured from the reflex attenuance at 525 nm (A525). The relative proportions of each pigment was determined using two different methods: the Krzywicki method based on the reflex attenuance values at 473, 525, 572 and 700 nm and the KS method based on K/S ratios of the absorption and scattering coefficients (K/S)474 ÷ (K/S)525, (K/S)572 ÷ (K/S)525 and (K/S)610 ÷ (K/S)525. The study was performed on beef (Longissimus lumborum) samples measured after 1, 4 and 7 days of exposure to air. Result revealed that L* values can be fully explained by A525 alone. C* and a* were well explained by those parameters related to OMb content. The other color parameters depended on pigment forms. The KS method gave better results. The parameters related to MMb content were relevant to classify samples according to the time of exposure to air. In any case, information provided by color and pigment parameters were complementary to each other.

Comparison between two different methods to obtain the proportions of myoglobin redox forms on fresh meat from reflectance measurements.

Two procedures based on reflectance (R) measurements to calculate the proportions of deoxymyoglobin (DMb), oxymyoglobin (OMb) and metmyoglobin (MMb) in meat are recommended by the American Meat Science Association (AMSA). One uses the K/S ratios (K and S are the absorption and scattering coefficients) and the other method (Krzywicki 1979) uses the reflex attenuance A = log (1/R). Both methods were compared in: a) synthetic sets of two pigment mixtures and b) 15 samples of beef Longissimus Lumborum measured after 24 h, 4 and 7 days of exposure to air. It was found that K/S and Krzywicki methods gave different values of pigment proportions. However both methods exhibited a high linear correlation (R(2) = 0.8733 in DMb, R(2) = 0.9771 in OMb and R(2) = 0.9390 in MMb, p < 0.0001). This makes them equivalent for statistical analysis based on differences in pigment proportions.

General expressions for the refractive indices of absorbing biaxial media as a function of the angle of incidence.

In this work we obtain general expressions for the complex refractive indices of refracted waves as a function of the angle of incidence in the case of an electromagnetic wave propagating in a transparent isotropic medium that reaches an interface with a biaxial absorbing medium. The biaxial absorbing medium is only required to have a diagonalizable complex dielectric tensor. Obtained expressions can be applied to any orientation of the principal axes and can be specialized for isotropic, uniaxial or biaxial, or transparent or absorbing media. By using these expressions we have also obtained the surface of indices and the surface of absorption coefficients for an example of a biaxial absorbing medium.

Methane digester effluent from swine excreta as a nutrient and water source for growing and finishing swine.

The experimental objective was to evaluate swine methane digester effluent (SMDE) as a water and nutrient source for swine. The mesophilic methane digester was loaded daily with manure from finishing swine fed a corn-soybean meal diet. Dry diet was mixed with SMDE (3.7% DM) and fed twice daily in troughs. Tap water was provided and consumption measured. Barrows were group fed (3 pigs/pen) and adapted to SMDE by increasing SMDE for 7 d, with the full amount fed from d 8 to the end of the feeding phase (d 21, 14, 23, or 37 for Exp. 1 to 4, respectively). Blood samples were collected on d 0, 10, 21, and 31 to determine plasma concentrations of glucose and plasma urea N (PUN). Barrows were placed in individual metabolism cages for a 5-d acclimation and a 5-d fecal and urine collection to determine apparent N and energy utilization. For Exp. 1, 18 pigs averaging 75 kg BW were allotted to diets with 0, 48.6, or 63.7% SMDE, as-fed basis. For Exp. 2 and 3, 12 pigs/experiment averaged 117 and 70 kg, respectively, and were allotted to diets with 0 or 63.7% SMDE, as-fed basis. At the end of Exp. 2 and 3, pigs were sacrificed and liver samples were collected to determine urea cycle enzyme activity, and loin was saved for taste panel evaluation. For Exp. 4, pigs averaged 40 kg and were allotted to diets with 0 or 57.5% SMDE, as-fed basis. The ADFI, ADG, and G:F of finishing swine (Exp. 1 to 3) were not reduced by feeding diets containing 63.7% SMDE (as-fed basis), whereas ADG and G:F of growing swine (Exp. 4) were reduced (P < 0.01) by feeding a diet containing 57.5% SMDE. Pigs fed diets containing SMDE consumed 31 to 56% less (P < 0.05) water and had greater (P < 0.01) PUN concentrations than pigs fed control diets. Pigs fed diets containing SMDE excreted more (g, P < 0.05) fecal N and absorbed and retained less N (%; P < 0.01) and energy (DE and ME) than pigs fed control diets. Treatment had no effect on urea cycle enzyme activity. In conclusion, finishing swine adapted to diets containing 63.7% SMDE (as-fed basis) based on growth performance, whereas growing swine did not adapt to a diet containing 57.5% SMDE because of the large content of nonprotein N in SMDE. Recycling SMDE to swine greatly reduced fresh water consumption, whereas the protein and energy values of SMDE were approximately 0 for swine. Therefore, SMDE is more appropriately recycled as a source of water and N for ruminant nutrition or crop production.

Effect of resistance training on resting metabolic rate and its estimation by a dual-energy X-ray absorptiometry metabolic map.

BACKGROUND/OBJECTIVES: Fat-free mass (FFM) is the major predictor of resting metabolic rate (RMR). As protein supplementation during resistance training may augment gains in FFM, we investigated the effects of resistance training combined with protein supplementation on RMR and whether RMR responses could be estimated by a dual-energy X-ray absorptiometry (DXA) metabolic map. SUBJECTS/METHODS: Healthy adults completed a whole-body periodized resistance training program consisting of 96 workouts (~9 months). Participants were randomly assigned to supplement with whey protein (whey; n=18), soy protein (soy; n=21) or carbohydrate (carb; n=22). RMR was measured using indirect calorimetry (RMR(IC)) and estimated by DXA metabolic mapping (RMR(MM)) pretraining and posttraining. RESULTS: RMR(IC) increased from pretraining to posttraining in the whole cohort (1653±302 to 1726±291 kcal/day, P=0.001) without differences between the groups. Delta RMR(IC) and RMR(MM) (73±158 vs 52±41 kcal/day were not significantly different by t-test (P=0.303), although they were not significantly correlated (r=0.081; P=0.535). Stepwise regression identified 43% of the shared variance in delta RMR(IC) using total serum thyroxine, RMR(IC) and FFM at baseline (P=0.009). CONCLUSIONS: These results indicate that 9 months of resistance training significantly increased RMR ~5% on average, but there was wide variability between individuals, which can be partially accounted for by changes in FFM and thyroid hormones.

Uniaxial absorbing media: conditions for refraction in the direction of the optical axis.

When a plane wave is incident from an isotropic medium into a uniaxial transparent medium so that the ordinary wave propagates in the direction of the optical axis, the extraordinary wave will also propagate in the same direction and with the same refractive index. We will show that this is not the case when the second medium is a uniaxial absorbing material. In this work, we will state a clear and precise interpretation of the meaning of propagation in the direction of the optical axis in the case of uniaxial absorbing media. Assuming that the ordinary wave is refracted in the direction of the optical axis we will analyze the refraction of the extraordinary wave and we will compare it with the case of transparent media. The necessary conditions to have both ordinary and extraordinary waves refracted in the direction of the optical axis will be obtained.

Molecular architecture and electrical properties in evaporated films of cobalt phthalocyanine.

Thin films of cobalt phthalocyanine (CoPc) were deposited onto solid substrates through physical vapor deposition (PVD) by thermal evaporation up to 60 nm thick to determine their molecular architecture and electrical properties. The growth was monitored using UV-Vis absorption spectroscopy, revealing a linear increase for absorbance versus thickness. PVD films were found in the crystalline alpha phase and with the CoPc molecules forming ca. 45 degrees in relation to the substrate surface. The film surface was fairly homogeneous at the micro and nanoscales, with the roughness at ca. 3 nm. DC and AC electrical measurements were carried out for devices built with distinct structures. Perpendicular contact was established by depositing 60 nm CoPc PVD films between indium tin oxide (ITO) and Al, forming a sandwich-type structure (ITO/CoPc/Al). The current versus DC voltage curve indicated a Schottky diode behavior with a rectification factor of 4.2. The AC conductivity at low frequencies increased about 2 orders of magnitude (10(-9) to 10(-7) S/m) with increasing DC bias (0 to 5 V) and the dielectric constant at 1 kHz was 3.45. The parallel contact was obtained by depositing 120 nm CoPc PVD film onto interdigitated electrodes, forming an IDE-structured device. The latter presented a DC conductivity of 5.5 x 10(-10) S/m while the AC conductivity varied from 10(-9) to 10(-1) S/m between 1 Hz and 1 MHz, respectively, presenting no dependence on DC bias. As proof-of-principle, the IDE-structured device was applied as gas sensor for trifluoroacetic acid (TFA).

Discriminación de la limitación al ejercicio en pacientes EPOC severa en pruebas máximas y submáximas / Discrimination of exercise limitation in submaximal and maximal exercise tests in severe COPD patients

No existe evidencia sobre la limitación por síntomas al ejercicio comparando pruebas máximas y submáximas en pacientes con EPOC. Objetivos: Comparar la referencia de limitación por disnea o fatiga entre una prueba de ejercicio máxima y submáxima. Métodos: Se incluyeron pacientes con EPOC moderada y severa (definición GOLD). Se clasificó como limitados por fatiga (LF) si en cicloergometría máxima tenían una diferencia = 2 puntos en la escala de Borg para fatiga de miembros inferiores vs. disnea. Se los clasificó como limitados por disnea (LD) por lo inverso. Se les realizó pruebas ergométricas submáximas, evaluándolos igual. Resultados: Se evaluaron 15 pacientes LD y 18 LF. En pacientes LF predominaban mujeres (LF 55.5 vs LD 26.6% p: 0.034), tenían menor índice peso/talla (LF 24.1 ñ 3.2 vs. LD 26.8 ñ 2.1; p<0.04) y menor obstrucción al flujo aéreo (LF 47 ñ 13.8% vs. LD 34.5 ñ 11.1%, p<0.047). En pacientes con LF, las pruebas máximas y submáximas fueron concordantes (Borg 2.8 ñ 2; 2.5 ñ 2.2, p=NS), pero no en aquéllos con LD (Borg 5.7 ñ 2.1; 3.3 ñ 1.6, p=0.014). Las pruebas submáximas son específicas (100%: fatiga y 93.3%: disnea) y tienen pobre sensibilidad (44%: fatiga y 35.7%: disnea) para clasificar a los pacientes en la causa de limitación. Conclusión: Los pacientes con LF presentan menor grado de obstrucción bronquial e índice peso-talla. En pacientes LF las pruebas máximas y submáximas fueron concordantes. Las pruebas submáximas son específicas pero tienen poca sensibilidad para clasificar por causa de limitación por síntomas. (AU)

There are no data about symptoms of activity limitation in COPD patients when maximal and submaximal exercise tests are compared. Objective: To compare the activity limitation by dyspnea or fatigue between maximal and submaximal exercise tests. Methods: Moderate and severe COPD patients were included (GOLD definition). They were classified as fatigue limited (FL) if Borg scale of fatigue at maximal exercise was = 2 points vs. dyspnea; and dyspnea limited (DL) if it was the reverse. Each patient was evaluated in the same way with submaximal cycloergometry. Results: 15 patients in the LD group and 18 patients in the LF group were evaluated. The LF patients were mainly women (FL 55.5 vs. DL 26.6% p: 0.034), had a low body-mass index (FL 24.1 ñ 3.2 vs. DL 26.8 ñ 2.1; p<0.04) and less airway obstruction (FL 47 ñ 13.8% vs. DL 34.5 ñ 11.1%, p<0.047). Maximal and submaximal tests were concordant in FL patients (Borg 2.8 ñ 2; 2.5 ñ 2.2, p=NS), but not in DL patients (Borg 5.7 ñ 2.1; 3.3 ñ 1.6, p=0.014). Conclusions: FL COPD patients had less airway obstruction and body-mass index. In FL patients both tests were concordant. The submaximal exercise tests are specific but they have low sensitivity to determine the cause of symptom limitation. (AU)

A retrospective review of the effect of surgeon specialty on the management of 190 benign and malignant pediatric and adolescent adnexal masses.

STUDY OBJECTIVE: To investigate the impact of operating surgeon specialty on rates of ovarian preservation, and to explore differences in surgical management when malignant lesions are identified. DESIGN: Retrospective study. SETTING: Education and research hospitals. PARTICIPANTS: Between January 1, 2003 and January 1, 2009, all female patients ≤ 20 years of age undergoing surgery with pathologically confirmed ovarian or fallopian tube tissues removed were evaluated. INTERVENTIONS: Demographic, operative, and pathologic data were abstracted. MAIN OUTCOME MEASURES: Rates of ovarian preservation with benign lesions, and rates of appropriate surgical staging when malignant lesions were identified. RESULTS: The mean age was 11.9 ± 4.4 years. Malignant lesions were larger than benign masses, 17.3 ± 7.1 cm versus 8.8 ± 7.1 cm respectively (P < .001). Torsion was associated with oophorectomy with a relative risk (RR) of 1.86 and 95% confidence interval (CI) of 1.35-2.57 (P = 0.033). Postmenarchal patients were less likely to undergo ovarian sacrificing procedures (RR 0.62, 95% CI 0.45-0.84, P < .001). The relative risk of incomplete surgical staging with malignant lesions was reduced in the presence of a gynecologic oncologist (RR 0.14, 95% CI 0.02-0.89, P = .003). CONCLUSION: Ovarian conservation should be prioritized in cases with benign lesions, whereas complete and accurate surgical staging is imperative when malignancy is identified.

Discriminación de la limitación al ejercicio en pacientes EPOC severa en pruebas máximas y submáximas / Discrimination of exercise limitation in submaximal and maximal exercise tests in severe COPD patients

No existe evidencia sobre la limitación por síntomas al ejercicio comparando pruebas máximas y submáximas en pacientes con EPOC. Objetivos: Comparar la referencia de limitación por disnea o fatiga entre una prueba de ejercicio máxima y submáxima. Métodos: Se incluyeron pacientes con EPOC moderada y severa (definición GOLD). Se clasificó como limitados por fatiga (LF) si en cicloergometría máxima tenían una diferencia = 2 puntos en la escala de Borg para fatiga de miembros inferiores vs. disnea. Se los clasificó como limitados por disnea (LD) por lo inverso. Se les realizó pruebas ergométricas submáximas, evaluándolos igual. Resultados: Se evaluaron 15 pacientes LD y 18 LF. En pacientes LF predominaban mujeres (LF 55.5 vs LD 26.6% p: 0.034), tenían menor índice peso/talla (LF 24.1 ± 3.2 vs. LD 26.8 ± 2.1; p<0.04) y menor obstrucción al flujo aéreo (LF 47 ± 13.8% vs. LD 34.5 ± 11.1%, p<0.047). En pacientes con LF, las pruebas máximas y submáximas fueron concordantes (Borg 2.8 ± 2; 2.5 ± 2.2, p=NS), pero no en aquéllos con LD (Borg 5.7 ± 2.1; 3.3 ± 1.6, p=0.014). Las pruebas submáximas son específicas (100%: fatiga y 93.3%: disnea) y tienen pobre sensibilidad (44%: fatiga y 35.7%: disnea) para clasificar a los pacientes en la causa de limitación. Conclusión: Los pacientes con LF presentan menor grado de obstrucción bronquial e índice peso-talla. En pacientes LF las pruebas máximas y submáximas fueron concordantes. Las pruebas submáximas son específicas pero tienen poca sensibilidad para clasificar por causa de limitación por síntomas.

There are no data about symptoms of activity limitation in COPD patients when maximal and submaximal exercise tests are compared. Objective: To compare the activity limitation by dyspnea or fatigue between maximal and submaximal exercise tests. Methods: Moderate and severe COPD patients were included (GOLD definition). They were classified as fatigue limited (FL) if Borg scale of fatigue at maximal exercise was = 2 points vs. dyspnea; and dyspnea limited (DL) if it was the reverse. Each patient was evaluated in the same way with submaximal cycloergometry. Results: 15 patients in the LD group and 18 patients in the LF group were evaluated. The LF patients were mainly women (FL 55.5 vs. DL 26.6% p: 0.034), had a low body-mass index (FL 24.1 ± 3.2 vs. DL 26.8 ± 2.1; p<0.04) and less airway obstruction (FL 47 ± 13.8% vs. DL 34.5 ± 11.1%, p<0.047). Maximal and submaximal tests were concordant in FL patients (Borg 2.8 ± 2; 2.5 ± 2.2, p=NS), but not in DL patients (Borg 5.7 ± 2.1; 3.3 ± 1.6, p=0.014). Conclusions: FL COPD patients had less airway obstruction and body-mass index. In FL patients both tests were concordant. The submaximal exercise tests are specific but they have low sensitivity to determine the cause of symptom limitation.

Tribological properties of Ti-based alloys in a simulated bone-implant interface with Ringer's solution at fretting contacts.

The wear properties of oxidized and non-oxidized gamma-TiAl (a potential biomaterial) as well as Ti-6Al-4V and CP-Ti disks were studied and characterized by means of standard wear tests using a custom made bone pin arrangement. The Ti-based disks were oxidized in air at 500 and 800 degrees C for one hour. The tribological properties of the oxides formed over the disks were studied using a linear reciprocating wear testing machine under both dry and simulated biological conditions using Ringer's solution. Loss of metal oxide and coefficient of friction values were determined from wear testing. From the results, abrasion and adhesion were the primary wear mechanisms in each of the three alloy-bone pairs. Specifically, the oxide formed on gamma-TiAl possessed the highest COF and wear resistance of the three materials which were studied. Also, as expected, bone wears down faster than the Ti-based metal oxide.

Influence of absorption on the anomalous negative refraction in right-handed uniaxial absorbing dielectric media.

In this work we study the anomalous negative refraction when a plane wave is incident from an isotropic medium to a uniaxial absorbing medium. We study the influence of the anisotropy on the refractive indices and the anisotropy on the absorption coefficients in the negative refraction of these materials. Negative refraction can occur for the ordinary and extraordinary waves for a wide range of values of the angle of incidence. The allowed values of the angle of incidence that lead to negative refraction are analyzed in detail as a function of the orientation of the optic axis and the values of the refractive indices and absorption coefficients.

Laser ablation single-collector inductively coupled plasma mass spectrometry for lead isotopic analysis to investigate evolution of the Bilbilis mint.

This work explores the performance of laser ablation-inductively coupled plasma mass spectrometry using different types of single-collector devices (sector field and time-of-flight instrumentation) for lead isotopic analysis of bronze coins, minted in the ancient city of Bilbilis. The aim of the study was achieving sufficient discrimination power to reveal similarities and differences for coins originating from different historical periods, and to obtain information on the possible source of the lead ores used in their production, while restricting the damage inflicted to the samples such that it is not visible to the naked eye. It was found that satisfactory results (RSD in the 0.15-0.30% range for (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios) could be finally obtained, despite the noisy nature of signals generated upon ablation of the highly inhomogeneous coins, by means of a methodology based on: (a) selection of the line profiling ablation mode; (b) use of a dual pass spray chamber that permits the simultaneous introduction of a solution (containing thallium of known isotopic composition), thus resulting in a wet plasma that showed an increased robustness towards matrix effects and (c) detection using a TOF-ICPMS unit, which proved to be much better suited to deal with the transient signals obtained, while being also sufficiently sensitive to obtain good counting statistics, owing to the high lead level (average around 5%) present in the samples. Moreover, under these conditions, the simultaneous aspiration of the thallium spike permitted accurate correction for mass discrimination, such that it was not necessary to use external matrix-matched standards for calibration.

Interface between transparent isotropic and uniaxial absorbing dielectric media: equations for ray tracing and for the direction of propagation.

In this work we analyze the propagation of a plane wave that passes from an isotropic transparent medium to a uniaxial absorbing medium. Detailed expressions that give the real directions of propagation of the wave and the energy of the reflected and refracted ordinary and extraordinary waves are obtained. These expressions are valid for every orientation of the optic axis of the uniaxial medium and for every direction of propagation of the incident wave. Expressions are tested in the case of an interface between a transparent and an absorbing isotropic media and for the air-rutile (TiO2) interface. The effect of absorption has been evaluated by comparing the results obtained in rutile with the results obtained in a transparent uniaxial medium with the same real refractive indices. Results are presented for different values of the angle of incidence and the orientation of the plane of incidence.